The touch panel technology progresses day by day. At present, the fabrication technology of touch panel is developing for being compatible with and integrated to the process of thin film transistor LCD (TFT LCD). In the form of a touch display module, the manufacturing cost and the thickness of touch panel can be reduced. The structures and processes of single-sided ITO (SITO), double-sided ITO (DITO), glass/film/film (GFF), or on glass sensor (OGS) according to the prior art are not compatible with the standard process of TFT LCD according to the prior art. This is because it is required to form an indium tin oxide (ITO) film or attach an ITO thin film material on one side of double sides of an extra glass or on a cover glass in the SITO, DITO, or GFF structures for routing the transmitting and receiving signals. Nonetheless, the method of using an extra glass for forming the conductive film or attaching the thin film material increases the overall thickness and weight of the touch display module. Besides, the pasting between two glasses or between a glass and a conductive thin film is required, which will reduce the yield of the touch display module and increase process complexity.
Thereby, for overcoming the technical problems described above, developers have developed the touch panel technology with a single electrode layer. The ITO film is formed on the other side of the cover filter glass. After the processes of lithography and etching, the routing of transmitting and receiving signals is completed simultaneously. Accordingly, the touch panel technology with a single electrode layer can reduce the risk of yield loss and the manufacturing costs.
Nonetheless, a general touch panel technology has much routing for transmitting and receiving signals. Likewise, the touch panel technology with a single electrode layer faces the same scenario. Consequently, for a general 5-inch touch panel with a single electrode layer, 352 wires are required for transmitting signals. Because the routing of the transmission lines is straight and there are as many as 352 wires for transmitting signals, when the touch panel is placed on the display panel for displaying, the problem of pattern visibility occurs. In other words, when a user views the image displayed on the display panel at certain angles, many stripes appear. In addition, 352 wires of transmitting signals need to be connected to the control integrated circuit (IC). The tremendous amount of wires greatly increase the area of the layout for the flexible printed circuit board connecting to the outside, and hence increasing difficulty in integrating the touch display module and a mobile device.
Accordingly, the present invention improves the design of the touch panel with a single electrode layer according to the prior art and solves the problems of pattern visibility and thickness.